The present invention relates to determining the remaining time a fluid in a container can be used. In particular, the present invention relates determining the remaining time a reagent in a reagent container on an automated diagnostic analyzer can be used.
Known diagnostic analyzers include immunodiagnostic analyzers such as the Vitros® ECi immunodiagnostic analyzer, or clinical chemistry analyzers such as the Vitros® 5,1 FS, both sold by Ortho-Clinical Diagnostics, Inc. All such analyzers are collectively called diagnostic analyzers.
Such analyzers typically use a source of reagent to react with a sample being analyzed to produce a measurable signal that can be determined through conventional means, such as light spectrophotometry, potentiometric or chemiluminescence analysis to name a few. Reagent containers (alternatively called reagent packs) are loaded and stored on the analyzer and are used as needed. The storage of the containers is generally under refrigerated conditions. The amount of reagent is usually based on the number of tests or analysis to be performed. For example, a reagent container may be filled with enough reagent to perform fifty or one hundred tests.
As reagent is used the remaining reagent in the reagent container decreases. As the amount of reagent decreases, the present inventor has found that the stability of the reagent decreases with the corresponding decrease in the amount of reagent. This is believed to be due to several causes such as instability that can result from the fact that lower remaining volume will evaporate more quickly resulting in a faster rate of reagent degradation.
For the foregoing reasons, there is a need for a method of determining the remaining time a fluid can be used in a process, particularly an analytical analysis.